Diagram showing the positions of the three principal cisterns in the brain. The cisterna cerebellomedullaris is labelled at the lower right.
|Anatomical terms of neuroanatomy|
The cisterna magna (or cerebellomedullaris cistern) is one of three principal openings in the subarachnoid space between the arachnoid and pia mater layers of the meninges surrounding the brain. The openings are collectively referred to as cisterns. The cisterna magna is located between the cerebellum and the dorsal surface of the medulla oblongata. Cerebrospinal fluid produced in the fourth ventricle drains into the cisterna magna via the lateral apertures and median aperture.
Cerebral spinal fluid can also be obtained by puncture of the cisterna magna (cistern puncture).